Motorola A3100 Troubleshooting Manual page 4

3.Check the voltage of R79
R79 > 3.4V
4. Check the power-on key path
N_KB_PWR_KEY (TP165) > 2.6V
If N_KB_PWR_KEY is low, the unit will power on.
> 3.4 V
Service Engineeing & Optimization
Level 3 , Rev.1.0
Can't Power On (2)
> 2.4 V